1. Technical Field
The present invention relates to a medium feeding device that feeds a medium, and an image reading apparatus and recording apparatus including the medium feeding device.
2. Related Art
An example of an image reading apparatus, namely a scanner, is given below. In some cases, a scanner is provided with a feeding device (also referred to as an auto document feeder (ADF)) that automatically feeds a document, which is an example of a medium, and is configured to be capable of automatically feeding and reading a plurality of documents.
Japanese Patent No. 4820314 describes a feeding device with such a configuration including a tray (“shooter 14” in Japanese Patent No. 4820314) in which a plurality of documents is mounted, a feeding roller (“setting roller 2” in Japanese Patent No. 4820314) that feeds the documents by contacting the surface of the documents set in the tray and rotating, and a separating roller (“setting roller 12” in Japanese Patent No. 4820314) that contacts the feeding roller and separates the documents.
The feeding roller described in Japanese Patent No. 4820314 is configured to sequentially feed documents from a sheet on a bottom side, that is, a sheet on the mounting surface side of the tray, of the plurality of documents (paper stack) stacked in the tray. A leading edge of upper sheets, that is, sheets to be separated, abut onto the separating roller and are restricted from being transported downstream.
While various systems for separating sheets exist, in some cases separation performance may be insufficient with only the separation obtained through a separator (main separator) such as those described above; and in some cases, to perform more reliable separation, a section for performing preliminary separation (sub separator) may be provided upstream of the separator. In recording apparatuses such as printers, as described in JP-A-2006-117384, for example, in some cases such configurations are employed that a ramp (bank separation portion) for separating sheets is provided at a location facing the paper leading edge in the feeding tray, and the number of sheets advancing to the main separator is reduced by this separation-use ramp.
While bank separating systems such as that described above have simple structures and can be manufactured at low cost, there is a disadvantage in that the bank separating systems may not be applied as-is to the feeding device of such a type that described in Japanese Patent No. 4820314, in which sheets are fed sequentially from the bottommost sheet instead of the topmost sheet of the set sheets.